This is a demo game for the Planet game engine by Blue 5alamander. A full version of the game is available on Android, Windows and Linux.
You'll need to have some development tools and libraries available. On Debian based systems (like Ubuntu) the following should suffice:
sudo apt install cmake build-essential libsdl2-dev libsdl2-ttf-dev
Then to clone and build, the following can be used:
git clone --recursive git@github.com:Blue5alamander/6nake.git
cd 6nake
cmake -B ./build.tmp -DCMAKE_BUILD_TYPE=Release .
make -C ./build.tmp
You can run it straight from the build tree without installing:
./build.tmp/6nake